In recent years, use of wireless local area networks (LANs) representative of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 has increased. Further, wireless LAN supporting products (hereinafter, also referred to as “wireless communication devices”) are also increasing accordingly. In contrast, there are limitations on wireless communication resources available for communication. Therefore, it is desirable to improve the efficiency of communication between wireless communication devices.
As an example of a technique for improving communication efficiency, a technique called “virtual carrier sense” is known. Specifically, a mechanism such as request to send (RTS)/clear to send (CTS) disclosed in Non-Patent Literature 1 is known. For example, a transmitting device that desires data transmission transmits an RTS frame to a receiving device serving as a destination of data transmission and checks whether or not data transmission is possible. Then, when a CTS frame is received from the receiving device, the transmitting device determines that data transmission is permitted, and starts data transmission. A wireless communication device other than the destination of the RTS frame or the CTS frame sets an NAV and stops data transmission during an NAV period. As a result, communication collision is prevented, and communication efficiency can be improved consequently.
Here, in Non-Patent Literature 1, the RTS frame is specified to be transmitted when a length of data desired to be transmitted is longer than a predetermined threshold value (dot 11RTSThreshold).